Examples of well-known conventional surface treatment agents for preventing deterioration of, coloring or otherwise treating the surface of such materials as plastics, woven fabric, non-woven fabric, wood, metal or ceramics include various organic coating materials generally comprised of high polymer resin, such as epoxy resin, varnish and paint, and inorganic coating materials generally comprised of such an inorganic material as silicate.
As an organic coating material does not have great resistance to weather damage, it is conventionally practiced to use a surface treatment agent containing an inorganic coating material when great weather resistance is required. However, inorganic coating materials have drawbacks in that the range of its usage is limited; although they are capable of coating ceramics well, they are not capable of forming a good coating film on such a base member as plastics, metal, wood, woven fabric or non-woven fabric.
An example to overcome this problem is disclosed in Japanese Patent Provisional Publication No. 43359/1981.
The method described in said Japanese Patent Provisional Publication No. 43359/1981 calls for coating a base member made of wood, metal, glass or concrete with a hardenable coating agent that is a mixture of a water-soluble or water-dispersible alkali metal silicate glass, a water-soluble base having a greater basicity than that of said alkali metal silicate glass, water, and 5 to 90 vol. % of a pigment by applying said coating agent onto the base member and letting the agent stand until it hardens.
In order to make the color of the pigment more uniform by ensuring thorough dispersion of the pigment, which tends to flocculate, the treating method disclosed in Japanese Patent Provisional Publication No. 43359/1981 calls for making a mixture by mixing a water-soluble or water-dispersible alkali metal silicate glass, which serves to have the base member to support the pigment, with water and a water-soluble base having a greater basicity than that of the alkali metal silicate glass, and then mixing the pigment into the mixture with a volume mixing ratio of 5 to 90%. This method, however, has such a drawback that it does not provide a good color coating layer: it presents the possibility of peeling resulting from external impact or stress and lacks water resistance, because the base member is coated by a layer of pigment that is merely formed on the surface of the base member. Furthermore, not only does it take a long period of time to attain a desired hardness but also requires operation for protecting the layer formed by application of the agent from damage and water until the layer becomes sufficiently solid.
An example of a surface treatment agent containing a compound that contains a plurality of carboxyl groups and is selected from the group consisting of organic acids and organic acid salt; a magnesium compound; either fine granular silica or a water-soluble substance containing silicic acid; and water is disclosed in Japanese Patent Provisional Publication No. 320284/1989.
The method described in said Japanese Patent Provisional Publication No. 320284/1989 is adapted to treat the surface of a calcium-containing inorganic material, such as concrete, and calls for adding water to a treatment agent containing a magnesium compound and a compound that contains a plurality of carboxyl groups and is selected from the group consisting of organic acids and organic acid salt, said treatment agent also containing either fine granular silica or a water-soluble substance containing silicic acid; and applying or spraying said mixture of water and treatment agent onto the surface of the calcium-containing inorganic material, such as concrete or mortar. Hardening the calcium-containing inorganic material under the presence of the water produces a water-soluble silicic acid compound from the sodium compound, the silica and calcium hydroxide contained in the concrete, while reaction of the organic acid or the organic acid salt with free magnesium ions and calcium ions generates organic magnesium and organic calcium. Because of the capillary phenomenon and the osmotic pressure, the water-soluble silicic acid compound and the organic calcium permeate capillary pores and gaps in the calcium-containing inorganic material, such as concrete. The organic acid or the organic acid salt that has permeated in the inorganic material and remains therein then acts as a catalyst to cause reaction between the water-soluble silicic acid compound and the calcium hydroxide in the calcium-containing inorganic material, such as concrete, thereby generating a compound containing calcium silicate. Furthermore, reaction of the organic magnesium and the organic calcium with the water-soluble silicic acid compound also generates a compound containing calcium silicate. The structure density of the calcium-containing inorganic material is increased with its capillary pores and gaps thus filled.
The treating method disclosed in Japanese Patent Provisional Publication No. 320284/1989, however, is intended for treating a calcium-containing base member, such as concrete, and not capable of forming a good coating film on a member such as plastic member, wood or woven fabric. Furthermore, the condition of the compound containing calcium silicate varies depending on the amount or conditions of the remaining organic acid and the organic acid salt, because they effect the aforementioned reactions and also permeate the capillary pores and the gaps. In other words, the method presents a problem of being complicated in procedure, because it necessitates meticulous setting of mixing ratio as well as precise control of the atmosphere for the reactions. Furthermore, it takes a long period of time to attain a desired hardness and requires operation for protecting the layer formed by application of the agent from damage and water until the layer becomes sufficiently solid.
In order to solve the above problems, an object of the present invention is to provide a surface treatment agent and a treatment method using such a treatment agent, said treatment agent and method being capable of treating any base member easily and quickly by means of a strong coating film so as to prevent deterioration of the surface of the base member. Another object of the invention is to provide a treatment agent and a method using the same, said agent and method being capable of coloring a base member easily and quickly by means of a strong coating film which has great resistance to weather and water damage.